several of the local Hobie 20 sailors here were willing when I asked them. But these are great sailors and are not so worried about a few seconds of corrected time, they know that in the right conditions they will beat an I 20. there number is 62.4 with just a spin and 62.0 with a square top.
with the I20 at 59.3 you are correct why do it. And the only answer I might guess is why not. If the goal is to sail faster and better than everyone else then what better than to try to sail over the numbers. besides the numbers are calculated not measured, until there is a real number for the hobie 20 w spin and or square top there is no way to say that it is not really faster.